This weekend’s demolition of the Welch Street Bridge in North Dallas will cause major lane closures along LBJ Freeway beginning tonight.

The bridge, just west of the freeway’s interchange with the Dallas North Tollway, was closed at 9 this morning to prepare for its removal.

Beginning at 8 p.m., the ramp from the tollway onto westbound LBJ will close, and drivers will be rerouted to the frontage road via the Alpha Road exit.

Westbound traffic will be reduced to two lanes from Midway Road to Montfort Drive until 5 p.m. Saturday, and two eastbound lanes will be closed between Rosser Road and the tollway during the same period.

At 5 p.m. Saturday, two lanes of LBJ will be closed in each direction between Midway and the tollway, as will the entrance ramp from Inwood Road to westbound LBJ. Those closures will remain in place until 5 a.m. Monday.

The demolition will wrap up Monday morning, and the new bridge will reopen in six months.

“If I was a commuter who typically travels westbound I-30, I’d be looking for an alternative route,” says TxDOT spokesman Mark Pettit.

The westbound lanes of I-30 and the St. Francis Bridge itself were shut down about 11 a.m. after an 18-wheeler with an oversized load “punched through the bridge deck” and damaged the pavement on I-30, Pettit said.

It could be several hours before crews can determine whether the bridge is structurally sound. On the bright side, no injuries were reported in the crash.

“I believe there were other vehicles involved” in the accident, he said, “but it doesn’t look like there have been any injuries.”

Original entry:

Westbound Interstate 30 in Far East Dallas has been closed after a semi struck the overpass at St. Francis Avenue.

All westbound traffic must exit the highway at St. Francis, while crews with the Texas Department of Transportation check the bridge for structural damage.Continue reading →

But when the signature bridge is dedicated, it’s going to be a “momentous occasion,” Coulter says.

The honorary chairs for the March celebration are to include former Dallas mayors Ron Kirk, Laura Miller and Tom Leppert. All were ardent supporters of the Trinity River project, of which the uncompleted bridge is a component.

PHOTO: Suspension cables being installed earlier this month on the Margaret Hunt Hill Bridge over the Trinity River. (JIM MAHONEY/DMN)

“The current design that we have for the bridge costs more than we have the means to pay for right now,” City Manager Mary Suhm told the City Council’s Trinity River project committee.

She added: “The bridge will be less expensive, therefore you shouldn’t expect four steel arches. Four steel arches are very expensive. But I really believe with his [Calatrava's] capabilities we will have a very striking bridge that we will all be proud of.”

The current design for the McDermott is shown below. The bridge, to be known as the Margaret McDermott Bridge, would span the Trinity River at Interstate 30.

The signature features of that bridge would cost about $200 million more than what the Texas Department of Transportation is willing to pay for a generic highway bridge. The city is far short of securing that amount through a combination of private and federal sources.

TxDOT, meanwhile, has said the existing I-30 bridge needs to be replaced. It hopes to begin construction on a new one by the summer of 2012.

Calatrava, of course, is also the designer of the Margaret Hunt Hill Bridge currently under construction at Continental Avenue. That bridge, when completed, will extend the Woodall Rodgers Freeway across the Trinity.

There are plans for a third Calatrava bridge over the river, at Interstate 35E. That bridge would run between the existing Jefferson and Corinth bridges.

However, as the city notes on its Trinity River project web page, only “a small amount of funding has been secured” for that bridge, and “design has not yet begun.”

PHOTOS: Top: A crappy looking wooden bridge that I found in our photo library. If you must know, it crosses Chartiers Creek in Pittsburgh. (AP). Above: The Margaret McDermott Bridge, which Dallas officials now say they can’t afford. Any new, cheaper design will probably not include the four arches, according to City Manager Mary Suhm. (The Trinity River Corridor Project)